After failing to get shareholders of MGM Mirage to cash in their chips, billionaire rebel investor Kirk Kerkorian may have to sweeten his offer if he wants to control more of the Las Vegas casino behemoth.

Kerkorian’s tender offer to buy 15 million shares of MGM from existing investors for $55 a share came up short yesterday, with only about a half-million shares tendered.

The 89-year-old sun-drenched financier said he would buy the shares that were tendered in order to increase his stake in MGM to nearly 60 percent.

Sources close to Kerkorian said he believes MGM’s shares are undervalued and he wants to own more. But he may wait a few weeks before making another tender offer. Sources also played down the prospect of Kerkorian making a bid to take the company private.

Still, J.P. Morgan gaming analyst Harry Curtis said MGM’s management does not have the desire to sell out, but Kerkorian “has the financial power” to take the company private.

“We believe it is likely that Kerkorian raises his tender offer to increase his stake, but it probably needs to be north of $58 a share,” Curtis said in a research note yesterday.

Shares of MGM, which owns several choice resorts along the Las Vegas strip, closed yesterday at $56.90, giving Kerkorian’s stake a value of roughly $9 billion.

Kerkorian announced his tender offer on Nov. 21, the same day he sold 14 million shares of General Motors after failing to persuade the struggling car maker to partner with Carlos Ghosn, head of Renault and Nissan.

Kerkorian, who sits on MGM’s board, lost over $300 million on his failed investment in GM.

MGM’s shares were trading around $49 a share at the time of his offer, but have since risen above $57 as a wave of mergers, including the $28 billion takeover of casino giant Harrah’s, have boosted nearly every stock in the gaming sector.